I only skimmed the article. But I agree with your worry that this looks to be instructions that could put anyone who follows them at even higher risk of pain.

I only skimmed the article. But I agree with your worry that this looks to be instructions that could put anyone who follows them at even higher risk of pain. The aesthetic of the web site doesn't give me a warm and fuzzy feeling about the quality of the tools being promoted. That said, I suspect a key point the author would make in response to our concern is that we can vigorously backup the server hosting our contacts and calendar when we host these ourselves. In fact, this point is precisely why I host so much of my own stuff: I can manage how data is handled. Synchronization notoriously sucks, and if some synchronization failure causes many records to suddenly vanish, it would be easier to restore those records from a self-maintained server than to plead with Google's support. I wouldn't know the first thing about recovering synchronization-scrubbed records from the devices themselves (e.g., an Android phone). I suppose it would attack your point about "better backup" by asking what value that backup has if you can't easily leverage it to restore on demand. Still, I feel your points about quality, redundancy, and uptime could not be easily countered.